For vehicles of which the power is all or partially provided by vehicle batteries, for example, pure electric vehicles or some types of hybrid vehicles, high capacity vehicle batteries generally need to be arranged in the vehicles to provide enough instantaneous power and endurance mileages as long as possible.
The vehicle battery will generate heat at work, an over high temperature will directly influence the working performance and the service life of the batteries, and even generates overheating, electrolyte overflow, fire, explosion and other potential safety accident hazards. In order to ensure the safety of the vehicle battery, vehicle and battery manufacturers spare no effort to adopt various measures, for example, the design of various anti-collision structures, the selection of flame retardant materials, the arrangement of the vehicle battery in a relatively safe position and the safety protection of the vehicle battery based on control strategies. However, once the vehicle battery is on fire, the above measures are basically invalid. Therefore, when the vehicle battery is in danger, how to ensure the safety of the vehicle battery and the vehicle to provide enough escape time for passengers and the like is particularly important.
A relatively good solution is to arrange a cooling system for cooling the vehicle battery, and use the cooling system to extinguish fire in the case of overheat and fire of the vehicle battery resulting from collision or short circuit or some other incompletely controllable reasons. As to this solution, however, cooling liquid of the cooling system needs to simultaneously have the cooling effect and the fire-extinguishing function on the vehicle battery, so that the requirements on the material of the cooling liquid are relatively high. Moreover, if the cooling system simultaneously has the cooling effect and the fire-extinguishing function on the vehicle battery, the existing cooling system needs to be reformed, thereby resulting in that the overall solution is relatively complicated.